[news.eclipse.newcomer] Re: java.lang.NoClassDefFoundError­: javax/mail/

[Eric Rizzo <eclipse@xxxxxxxxxxxx>]

BillB wrote:
> I'm running an app under Eclipse 3.0.2 and getting the following runtime 
> error: java.lang.NoClassDefFoundError­: javax/mail/Session
>
> with the following line of code: session = 
> Session.getDefaultInstance(pro­ps, null);
>
> The app compiles without a problem.
>
> The jar files necessary for the app and another accompanying app are in 
> project called 'lib'. The lib project is is included in the Java Build 
> Path for this project, though I don't think that is relevant.
>
> Where else would Eclipse be looking for the mail.jar during runtime? 
> I've also added the location of the jar files to my system classpath but 
> the error still occurs.

The build path settings are separate from the runtime (called 'Launch' 
in Eclipse vernacular) classpath.
How are you launching the application? If you select the Run... menu 
item you can view/edit the Launch configuration, including the classpath 
it uses at runtime.

HTH,
	Eric